Expansible mandrel employing leaf springs to bias its sections into its pile entering relationship

ABSTRACT

An expansible mandrel is disclosed of the type provided with power operated means by which the mandrel sections are forced into their pile-gripping relationship and with means resiliently biasing the sections towards their pile-entering relationship, each in the form of a leaf spring extending lengthwise of the mandrel and connected at its ends to one mandrel section with the other mandrel section having a member so engaged with the central part of the leaf spring as to tension it as the the mandrel sections are forced apart into their pile-entering relationship.

United States Patent [191 Guild et al.

[451 Dec. 18, 1973 EXPANSIBLE MANDREL EMPLOYING 3,064,439 1l/l962 Cobi(SI/53.72 LEAF SPRINGS T0 BIAS ITS SECTlONS FOREIGN PATENTS ORAPPLICATIONS INTO ITS FILE ENTERING RELATIONSHIP 1 I09 412 4/1968 GreatBritain 242/72 [76] Inventors: Charles L. Guild, 7 Stone Tower 'Ln.,Barrmgton, R1. 02806; Willard Primary Examine, ]acob Shapiro B. Goodman,R0. BOX NO. 62, An0rney Abbott Spear Newport oreg. 97365 [22 Filed: Apr.3, 1972 [57] ABSTRACT PP ,381 An expansible mandrel is disclosed of thetype provided with power operated means by which the man- 52 us. Cl(El/53.72, 242/72, 279/2 i 2" faced l? their P?' 51 Int. Cl E02d 7/30tmshp and means reshemly basmg the seams [58] Field of Search 61/53.?2;242/72; Wards their P- each in 279/2 form of a leaf spring extendinglengthwise of the mandrel and connected at its ends to one mandrelsection [561 232;: 3:22;:21111 32229222; $22 52; i8 UNITED STATESPATENTS tension it as the the mandrel sections are forced apart3,264,834 into their pile entering relationship 777,780 l2/l904 Easton242/72 3,000,337 9/1961 Schpatz 242/72 12 Claims, 6 Drawing Figures f;y, X I H B 7 5 gr s N E14 Q I" z \c 5 id 1 2 a a t2. 2' g 49 48 49 $42 L6: 6'9 238 41; 5/ 4g 48 45 9 7/ 7 12:7 7 1 *"r 'i 125 I *7'T"""7""/"'7'7' 1 f""" j 'f/T/"Wi' r -r L 66 17 I 9 I V v. 2; l .2 j 7 W I H \TV W Il i 1 4B 3? 3 35 PATENTEU use 1 8 ms SHEUZBFZ FIG 5 BACKGROUND OF THEINVENTION umandrel sections into their pile-gripping relationship;

inflatable means, mechanically operated linkage, and also, the variousmeans disclosed in our co-pending ap plication Ser.No. l l,786, filedJune I0, 1971, a continuation-impart of our application Ser. No.824,631, filed May 14, 1969, and now abandoned. The means disclosed insaid co-pending application utilize a plurality of members within andspaced lengthwise of the .mandrel with flexible means in trainedengagement therewith and operable on a pull thereon in a predetermineddirection then to move the members to exert opposite forces on themandrel sections, in the case of the present invention, to effect theirpile-gripping relationship.

Means resiliently biasing the sections into their pileenteringrelationship that have proved effective required that the mandrelsections be interconnected at spaced intervals along their sides by rodsextending through oppositely opening, aligned pairs of sockets with nutsthreaded thereon confining compression springs against the bottoms ofthe sockets. This construction requires bores through the main arcuateportions of the mandrel sections and these, even when the sockets atopposite sides are not transversely aligned, result in troublesomestress rises.

THE PRESENT INVENTION The objective of the present invention is theprovision of expansible mandrels in which the means biasing the mandrelsections into their pile-entering relationship are more effective and atthe same time avoid the creation of previously mentioned stress problemsthat were previously encountered.

In accordance with the invention this objective is attained with amandrel for use in driving or withdrawing tubular piles and the like,the mandrel having longitudinal sections interconnected by a head. Aplurality of axially spaced means within the mandrel are operable toforce the sections into their pile-gripping relationship and the mandrelincludes at least one and typically a plurality of means resilientlybiasing the sections into their pile-entering relationship in yieldableopposition thereto and located in an intermediate space or spaces withinthe mandrel. Each resilient means is wholly within ithe mandrel and inpreferred embodiments includes a leaf spring extending lengthwise of themandrel with its ends connected to one mandrel section and with meansconnected to the other mandrel section and so engaging the central partof the leaf spring as to exert a tensioning pull thereon as the sectionsare forced into their pile-gripping relationship.

Resilient means biasing the mandrel sections into theirpile-enteringrelationship not only eliminate the previously encountered troublesomestress rises but also result in a more effective force distributioncentered lengthwise of the mandrel.

THE PREFERRED EMBODIMENT OF THE INVENTION The preferred embodiment ofthe invention is disclosed in the accompanying drawings in which FIG. Iis a somewhat schematic view of ,a mandrel taken lengthwise of itssections;

FIG. 2 is a section, on an increase in scale, taken approximately alongthe indicated line 2-2 of FIG. 1;

FIG. 3 is a fragmentary and partly sectioned view, with the mandrelturned from its FIG. 1 position, showing the connection between thefluid pressure operated means and the actuating cable;

FIG. 4 is a view on a further increase in scale, taken approximatelyalong the indicated line 4-4 of FIG. 1;

FIG. 5 is a section taken approximately along the indicated line 5-5 ofFIG. 1; and

FIG. 6 is a section taken along the indicated line 66 of FIG. 1.

In FIG. 1, an expansible mandrel is shown that has a .pair of arcuatesections 10, each of substantial length a drive head, generallyindicated at 11 and provided.

with an outwardly disposed flange 12, but otherwise not detailed as itmay be of any conventional type. The upper end of each section 10 has areinforcement 13, shown as an internal reinforcement, and also has anend plate 14 welded thereto providing an outwardly disposed flangeportion l5 securely clamped to the head flange 12 by means of boltsl6which also secure an interposed, inwardly tapered shim or wedge sections17. The thus attached ends of the mandrel section 10 are spaced apartbut the shims l7 bias them inwardly towards each other a short distancebelow the head.

The end plates 14, when the mandrel sections 10 are secured to the head11, establish abutting portions defining an axial passageway 18, seeFIG. 3, and supporting a concave seat member 19 receiving acomplemental, spherical washer 20. A bolt2l extends freely down wardlythrough the passageway 18 and has a locked nut 22 on its upper endseated against the washer 20. Links 23 are connected by a pivot 24 tothe other end of the bolt 21 and by a pivot 25 to the hanger 26 of afluid pressure operated ram 27 with the hanger 26 extending between themandrel sections 10 thereby to prevent the supported ram 27 fromturning.

The stem 28 of the ram 27 has a fork 29 to which a hanger 30 is securedby apivot 31. Links 32 are connected to the hanger 30 by a pivot 33disposed at right angles to the pivot 31 and rotatably support asprocket 34. A chain 35 is trained about the sprocket 34 and each endthereof with its ends attached to the appropriate one of a pair of yokes26, each rotatably supporting a sheave 37. i

The other ends of the mandrel sections 10 are closed by boot portions 38and one has an intermediate key -3 member 39 welded thereto slidablyentrant ofa keyway 40 in an intermediate member 41 welded to the othermandrel section thereby to prevent misalignment of the boot ends of thesection as the sections are moved between their pile-entering and theirpile-gripping relationships.

The mandrel sections 10, in order to effect the pilegrippingrelationship thereof, are connected by operating means spaced lengthwiseof the mandrel and including, as the flexible means, a pair of cables 42and a plurality of sheaves 43 and 44 arranged in groups. The sheaves 43and 44 are alternately disposed in each group with the sheaves 43connected to one mandrel section and the sheaves 44 connected to theother mandrel section. The number of sheaves in each group may vary asmay the distance between them, preferably with the largest number ofsheaves in the lower end of the mandrel and with the space between thegroups increasing towards the upper end thereof to ensure theapplication of maximum force in the lower portion of the mandrel as theresistance of the earth to its penetration increases with its depth.

Each mandrel section has internal reinforcements 45 extending lengthwisethereof throughout most of the length of the mandrel and of a rightangular section welded in positions to define a central channel 46 forthe sheaves and the cables. The reinforcements 45 of each section havetransversely aligned pairs of bars defining seats 47.

Each of the sheaves 43 and 44 has four grooves and is rotatablysupported in a U-shaped mount 48 shaped and dimensioned for slidableentry into an appropriate one of the seats 47 and to bear against themandrel section that forms the bottom of that seat with each sheavedimensioned to extend into the opposite channel 46 with clearancebetween it and the bottom thereof when the mandrel sections are in theirpile-gripping relationship. The mounts 48 have guide rollers 49 arrangedto hold the cable courses in the appropriate sheave channels, the endmounts having but one such guide roller and the intermediate mount ormounts having both infeed and outfeed guide rollers.

A bottom sheave 50, having four grooves, is supported in a mount 51welded to the key member 30 and to the section 10 of which it is a part.Above the uppermost group of sheaves there is a mount 52 welded to onesection 10 provided with anchors 53 for both ends of both cables 42. Themount 52 is also provided with a four groove sheave 54 and a guideroller 55 adjacent a four groove sheave 56 whose mount 57 is welded tothe other section 10 and also having a guide roller 58. The cables 42have both of their ends connected to the anchors 53 and both ends ofboth cables 42 are trained in the same manner about the sheaves of theseveral groups in succession and about the sheave 50. It will be seenthat the cable courses are sinuous as alternately they pass part wayaround the sheave 43 and then part way around a sheave 44 with theengaged portion of each sheave being that which is within the channel 46of the section 10 to which it is not attached so that a pull on thecables tends to straighten them and, in so doing, forces the mandrelsections 10 into their pilegripping relationship. The intermediatecourse of each cable 42 extends from the bottom end of the mandrelupwardly between the sheaves 54 and 56 and is trained about theappropriate sheave 37 and then between the sheaves 54 and 56 to thebottom of the mandrel.

With this arrangement, when the fluid pressure controls (not shown) areoperated to effect the retraction of the ram stem 28, an upward pull isexerted that effects a straightening pull on the portion of the cablesin trained engagement with the groups of sheaves 43 and 44 therebyforcing the mandrel sections 10 apart from their pile-enteringrelationship into their pile-gripping relationship.

The mandrel sections 10 are resiliently biased into their pile-enteringposition when the ram controls are again actuated to advance the ram 28thus relaxing the cables 43. At the bottom end of the mandrel, the meansfor urging the free ends of the mandrel sections together are of thetype previously used throughout the length of the mandrel. As may bestbe seen in FIG. 2, the member has outwardly opening sockets 59 adjacentits sides each aligned with a corresponding one of the outwardly openingsockets 60 with which the member 41 is provided. Rods 61 slidablyinterconnect the members 39 and 41 through the aligned sockets and nuts62 threaded thereon hold compression springs 63 against the bottoms ofsaid sockets.

In accordance with the invention, the means spaced lengthwise of themandrel to resiliently urge its sections 10 into their pile-enteringrelationship are generally indicated at 64 and each is located in aselected space between groups of sheaves 43 and 44. v

Each of the resilient means 64 has a leaf spring 65 shown as having oneend closed upon itself to provide an eye 66 and the other end doubled toestablish a slot 67. U-shaped anchoring mounts 68 are provided, one foreach end of the leaf springs 65 and welded to the reinforcements 45 ofone section 10. Each mount 68 has a pin 69 with the pin 69 of one mountextending through the eye 66 and the pin 69 of the other mount extendingthrough the slot 67. As will be apparent from FIG. 6, the base of eachmount 68 serves as a spacer for the intermediate courses of the cables42. A transverse pin' 70, carried by plates 71 welded to thereinforcements 45 of the other mandrel section 10, underlies the centralpart of each leaf spring 65 with its engagement therewith tensioning itas the mandrel sections are forced apart into their pile-grippingrelationship. The central part of each spring 65 is of a width fittingbetween the plates 71 and its width is shown, see FlG. 5, as taperinginwardly towards its ends.

As the resilient means 64 do not require that holes be bored through themandrel sections 10, previously experienced stress rises do not occur.It should be here noted that troublesome stress problems do not occurwith the spring arrangement at the bottom end of the mandrel as thesockets are in the members 39 and 41 and not in the main arcuate portionof the mandrel section 10. It will also be appreciated that theresilient means are of a simple rugged construction and that the forcesapplied by each spring 65 are in zones spaced lengthwise from each otherin an axial plane centrally of the sections.

We claim:

1. An expansible mandrel for use in driving or withdrawing tubular pilesand the like, said mandrel comprising longitudinal sections, a headconnecting the upper ends of the sections, a plurality of axially spacedmeans within the mandrel and operable to force the sections from theirpile-entering relationship into their pile-gripping relationships, andat least one means resiliently biasing the sections into theirpile-entering relationship and located in a space between the firstnamed means and including a leaf spring extending lengthwise of themandrel. connections between each end of the leaf spring and one of themandrel sections, and an intermediate member connected to the other ofsaid mandrel sections and so engaged with the central part of said leafspring as to hold said central part against independent movement towardone mandrel section thereby to exert a tensioning pull thereon as thesections are forced into their pile-gripping relationship.

2. The expansible mandrel of claim 1 in which the connections includetransverse pins, the leaf spring has an eye at one end through which onepin extends and a slot at the other end through which the other pin extends.

3. The expansible mandrel of claim 2 in which the intermediate memberis.a transverse pin underlying said central part.

4. The expansible mandrel of claim 1 in which the width of the leafspring decreases from the central part towards both of its ends.

5. The expansible mandrel of claim 1 in which the mandrel sectionsinclude lengthwise reinforcements and the connections and theintermediate member are secured to the reinforcements of the appropriateone of the mandrel sections.

6. The expansible mandrel of claim 5 in which each mandrel sectionincludes a reinforcement extending lengthwise of each side and defines acentral channel, the connections extend into one channel and are weldedto the reinforcements that define it, and the intermediate memberincludes supports entrant of the other channel and welded to thereinforcements that define it.

7. The expansible mandrel of claim 6 in which the spaced means that areoperable to force the sections into their pile-gripping relationship areall operated by at least one flexible member common to all of them andincluding one course connected to them in series and another courseextending parallel thereto, both courses within said one channel and theconnections are U- shaped with their closed ends within said one channeland separating the courses.

8. The expansible mandrel of claim 1 in which there is one resilientmeans between each two of the axially spaced means.

9. An expansible mandrel for use in driving or withdrawing tubular pilesand the like, said mandrel comprising longitudinal sections, a headconnecting the upper ends of the sections; a reinforcement extendinglengthwise of the interior of each section, a plurality of axiallyspaced means within the mandrel and operable to force the sections intotheir pile-gripping relationship, and at least one means resilientlybiasing the sections into their pile-entering relationship and locatedbetween the first named means and wholly within the mandrel sections andconnected to the reinforcements resiliently biasing means is centrallyof the mandrel sections.

11. The expansible mandrel of claim H) in which the resiliently biasingmeans is arranged to apply retractingforces in longitudinally spacedzones.

12. The expansible mandrel ofclaim 9 in which the reinforcements extendalong each side of each section. =k. =l=

1. An expansible mandrel for use in driving or withdrawing tubular pilesand the like, said mandrel comprising longitudinal sections, a headconnecting the upper ends of the sections, a plurality of axially spacedmeans within the mandrel and operable to force the sections from theirpile-entering relationship into their pile-gripping relationships, andat least one means resiliently biasing the sections into theirpile-entering relationship and located in a space between the firstnamed means and including a leaf spring extending lengthwise of themandrel, connections between each end of the leaf spring and one of themandrel sections, and an intermediate member connected to the other ofsaid mandrel sections and so engaged with the central part of said leafspring as to hold said central part against independent movement towardone mandrel section thereby to exert a tensioning pull thereon as thesections are forced into their pile-gripping relationship.
 2. Theexpansible mandrel of claim 1 in which the connections includetransverse pins, the leaf spring has an eye at one end through which onepin extends and a slot at the other end through which the other pinextends.
 3. The expansible mandrel of claim 2 in which the intermediatemember is a transverse pin underlying said central part.
 4. Theexpansible mandrel of claim 1 in which the width of the leaf springdecreases from the central part towards both of its ends.
 5. Theexpansible mandrel of claim 1 in which the mandrel sections includelengthwise reinforcements and the connections and the intermediatemember are secured to the reinforcements of the appropriate one of themandrel sections.
 6. The expansible mandrel of claim 5 In which eachmandrel section includes a reinforcement extending lengthwise of eachside and defines a central channel, the connections extend into onechannel and are welded to the reinforcements that define it, and theintermediate member includes supports entrant of the other channel andwelded to the reinforcements that define it.
 7. The expansible mandrelof claim 6 in which the spaced means that are operable to force thesections into their pile-gripping relationship are all operated by atleast one flexible member common to all of them and including one courseconnected to them in series and another course extending parallelthereto, both courses within said one channel and the connections areU-shaped with their closed ends within said one channel and separatingthe courses.
 8. The expansible mandrel of claim 1 in which there is oneresilient means between each two of the axially spaced means.
 9. Anexpansible mandrel for use in driving or withdrawing tubular piles andthe like, said mandrel comprising longitudinal sections, a headconnecting the upper ends of the sections, a reinforcement extendinglengthwise of the interior of each section, a plurality of axiallyspaced means within the mandrel and operable to force the sections intotheir pile-gripping relationship, and at least one means resilientlybiasing the sections into their pile-entering relationship and locatedbetween the first named means and wholly within the mandrel sections andconnected to the reinforcements thereof.
 10. The expansible mandrel ofclaim 9 in which the resiliently biasing means is centrally of themandrel sections.
 11. The expansible mandrel of claim 10 in which theresiliently biasing means is arranged to apply retracting forces inlongitudinally spaced zones.
 12. The expansible mandrel of claim 9 inwhich the reinforcements extend along each side of each section.